Flat display apparatuses are currently undergoing active development, particularly liquid crystal displays, which are finding application in various fields by dint of such desirable features as lightness, thinness, and low energy consumption. A liquid crystal display is realized by confining a liquid crystal layer between paired substrates, the display producing an image as a result of the modulation factor of light passing through the liquid crystal layer being controlled in accordance with an electric field between a pixel electrode and a common electrode.
For liquid crystal display apparatuses, there are known a method of controlling the liquid crystal alignment state by applying, to the liquid crystal layer, a longitudinal electric field in a direction almost perpendicular to the substrate surfaces of the paired substrates, and a method of controlling the liquid crystal alignment state by applying, to the liquid crystal layer, a transverse electric field (including even a fringe electric field) in a direction almost parallel to the surfaces of the paired substrates.
One of paired substrates includes driving interconnections for driving display pixels arrayed in a matrix, switching elements, a transparent organic insulating film (to be referred to as a planarization film hereinafter) arranged on the driving interconnections and pixel switches, and a conductive layer arranged on the planarization film.
A structure using a transverse electric field especially receives attention in terms of a wider view angle. A transverse electric field liquid crystal display apparatus in the in-plane switching (IPS) mode, fringe field switching (FFS) mode, or the like includes pixel electrodes and common electrodes formed on an array substrate. Liquid crystal molecules are switched by a transverse electric field almost parallel to the major surface of the array substrate.